Consulta: subjectFacets:"Radioactive tracers"
Registros recuperados: 4
Data/hora: 18/05/2024 10:17:59

Concentración de Cesio-137 en dos perfiles de suelo en el área de Bahías Almirantazgo y Chile
Provedor de dados: 20
Autores: Schuller, P.; Lovengreen, Ch.; Vega, M.
Durante la Segunda Expedición Ecuatoriana a la Antártida, enmarcada en el proyecto de evaluación de radionucleídos en las Islas Shetland del Sur, se tomaron dos perfiles de suelo correspondientes a Bahía Almirantazgo, Isla Rey Jorge, y a Punta Fort Williams, Bahía Chile, Isla Greenwich. Las muestras fueron procesadas en la Universidad Austral de Chile. Los trabajos realizados en dichos perfiles son: Determinación de la concentración de Cs-137 y algunas características edáficas relevantes. Las muestras tomadas de un perfil practicado en Bahía Almirantazgo, se caracterizaron por una actividad superficial de Cs-137 considerablemente superior a la predicha para la banda latitudinal correspondiente. La penetración del Cs-137 es favorecida por la geomorfología y...
Tipo: Journal Contribution
Palavras-chave: Radioisotopes; Radioactive tracers; Radioactive contamination; Polar zones; Radioisotopes; Radioactive tracers; Radioactive contamination.
Ano: 1990
URL: http://hdl.handle.net/1834/3867

Contributions des traceurs radioactifs a l''etude des mouvements sedimentaires en Baie de Seine
Provedor de dados: 5
Autores: Avoine, J; Caillot, A; Hoslin, R; Larsonneur, C; Massias, L; Quesney, M.
Sediment dynamics have been studied from 1979 to 1984 by the use of radio active tracers, to quantify sediment transport and to know the limits of tides and swell action in terms of sediment composition and depth. This technique has allowed the study of sand drifting (between -2 m and -15 m) and resuspension of muddy sediments. The effects of sediment movements on estuarine sediment accumulation are included in this report.
Tipo: Text
Palavras-chave: Radioactive tracers; Sediment movement; Sediment dynamics.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/acte-1285.pdf

Nutrition experimentale: Problemes methodologiques lies a l'utilisation des microorganismes comme source trophique
Provedor de dados: 5
Autores: Guidi, L.
The present study deals with technical problems encountered under lab conditions in studies of trophic relations between deposit-feeding invertebrates and microorganisms. Using 2 pure cultures of Pseudomonas and Navicula , it was shown that these microorganisms will attach to artificial (glass beads) and natural (sand grains) substrates. Best microbial attachment was observed on sand (up to 4.8 x 10 super(8) cells.g super(-1) dry wt.). The radioactive labelling of the microorganisms depends not only on the form under which the isotope ( super(14)C) is supplied to the cultures, but also on the time and the duration of the labelling. 70% of the isotope was incorporated in a stable manner by the diatoms. The bacteria incorporated, at most, 34% of the...
Tipo: Text
Palavras-chave: Navicula; Pseudomonas; Bacillariophyceae; Algae; Bacteria; Biological attachment; Radioactive tracers; Methodology; Microorganisms; Trophic relationships; Microbiological culture; Zoobenthos; Nutrition.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-987.pdf

Zooplankton nutrition study under conditions close to natural with the use of radioactive phosphorus
Provedor de dados: 5
Autores: Pavlovskaya, T; Zesenko, A.
Lack of a sensitive method for in situ study of the nutrition quantitative characteristics (and food balance in particular) for zooplankton populations in low-productivity regions was the reason for developing one. For the basis of such a method the authors selected the property of radioactive phosphorus isotopes of fast and effective embedding into all plankton components. The method described above allowed not only to quantitatively determine the consumption and transportation of a substance by individual species and populations of zooplankton; it opens new horizons for investigation of the zooplanktonic association role in regeneration of mineral phosphorus.
Tipo: Text
Palavras-chave: Phosphorus cycle; Phosphorus isotopes; Radioactive tracers; Analytical techniques; Food consumption; Zooplankton; Nutrition.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1524.pdf